Lymphoreticular system - lymph nodes

Question 1

B cell function

Answer 1

produce antibodies

Question 2

T cell function

Answer 2

• CD8+ cytotoxic T cell: direct killing of foreign/ infected cells
• CD4+ T lymphocytes: secrete cytokines - fine control of immune response

Question 3

NK cells

Answer 3

innate immune system - immediate, no memory

kill cells via apoptosis/ necrosis

Question 4

non-neoplastic diseases of the lymph node

Answer 4

• infection
• Necrotizing lymphadenitis (Kikuchi’s lymphadenitis)
• Drug related lymphadenopathy
• Autoimmune diseases: RA, SLE

Question 5

causes of infection of lymph node

Answer 5

• Acute non-specific lymphadenitis: Staphylococcus

- Granulomatous
	Mycobacterium
	Fungal infection
	Cat-scratch
	Lymphogranuloma Venereum
	Sarcoidosis (only suspect after excluding possibility of all the above infectious causes first)

• Viral: Infectious mononucleosis

Question 6

identification of granulomatous infection**

Answer 6

central caseating necrosis
multinucleated giant cell
collection of epithelioid histocytes

Question 7

autoimmune diseases (just name a few)

Answer 7

Myasthenia gravis, 
Graves's disease, 
Primary biliary cirrhosis, 
Autoimmune hemolytic anemia, 
Idiopathic thrombocytopenic purpura, 
Goodpasture's syndrome, 
Rheumatoid arthritis,
Sjogren's syndrome, 
Systemic lupus erythematosus (SLE)
Scleroderma,

Question 8

lymphomas

- clinical presentation

Answer 8

Enlarging mass(es), typically painless, at sites of nodal tissue - rapidly expanding

Compression/ infiltration of hollow organs -> pain, obstruction, perforation

Interference with normal organ function: Solid organ infiltration (kidneys, liver, bone marrow)

Systemic symptoms (fever, night sweats, weight loss)
[B symptoms - poor prognosis]

rapidly expanding necrotic mediastinal mass

Question 9

lymphoma staging

Answer 9

1: just 1 lymph node involved
2: 2 or more lymph nodes, same side
3: both sides
4: involves other organs

Question 10

aggressive lymphomas characteristics

Answer 10

• accelerated replication (defective cell cycle control)
• localised
• shorter natural history, which also means present at earlier stage
• curable w/ aggressive treatment (cause diagnosed early)

Question 11

indolent lymphomas characteristics

Answer 11

• slow replication (slow accumulation)
• widespread at diagnosis
• prolonged natural history = late presentation
• incurable
  (unless use stem cell transplant)

Question 12

WHO classification of lymphomas

Answer 12

• non Hodgkin lymphoma
  B cell
  T/ NK cell
• Hodgkin lymphoma
  classical
  nodular lymphocyte predominant

Question 13

B cell lymphomas

- 2 types

Answer 13

• immature
• mature:
  diffuse large B cell lymphoma (DLBCL)**
  follicular lymphoma
  Burkitt lymphoma

Question 14

diffuse large B cell lymphoma (DLBCL) characteristics

• treatment
• histo

Answer 14

most common lymphoma (30%)

• diffused growth pattern
• large cell size
• rapidly enlarging mass
• aggressive behavior

Diffuse infiltration of lymph node, large lymphoid cells, prominent nuclei
surface antigen: CD20+

Question 15

Burkitt lymphoma characteristics + appearance

• who does it affect
• pathogenesis

Answer 15

• starry sky appearance (associated w/ aggressive lymphomas) :
  Diffuse infiltration of lymph node, high cell turnover → attracts macrophages to phagocytose → starry sky pattern at low power
• presents as infection/ immune deficiency conditions
• very aggressive and rapidly fatal
• children and adults (~30)
• upregulation of myco-oncogene (affects cell cycle regulation)

surface antigens: CD20/10

Question 16

follicular lymphoma characteristics

• treatment
• pathogenesis
• histo

Answer 16

indolent lymphoma

• widely disseminated, even found in bone marrow
• incurable, unless w/ bone marrow transplant
• Upregulates expression of anti-apoptotic (wont die) protein Bcl2 = immortalisation of lymphoma cells

Retain characteristic follicular structure, but monotonous accumulation of single cell type

surface antigens: CD20/10, Bcl2**

Question 17

hodgkin lymphoma definition

Answer 17

Lymphoid neoplasm composed of Reed-Sternberg cells (neoplastic) residing in an inflammatory (non-neoplastic) background (w/ lymphocytes, histiocytes, eosinophils and plasma cells)

Question 18

classical hodgkin lymphoma

• who it affects
• histo appearance
• spread

Answer 18

• late adolescence (esp in poor countries)/ 60s
• Reed-Sternberg cells (neoplastic)
• background inflammatory cells
• spread via lymphatics
  contiguous spread - hallmark

Question 19

treatment of hodgkin lymphomas

Answer 19

• low stage: radiation therapy
• high stage: multi-agent chemotherapy w/ radiation therapy
• majority curable

Question 20

cause of hodgkin lymphomas

Answer 20

altered B cell: doesn’t express the normal B cell markers

Question 21

clinical investigations of lymph node enlargement (4)

Answer 21

- FNAC (fine needle aspirate cytology)
not really definitive, only used if pt cannot undergo anesthesia for biopsy 
- Biopsy
- culture
- serology

Question 22

tumour metastasised to the lymph nodes

Answer 22

very common
can be via lymphatics/ hematogenous spread

need to be careful in identifying tumours!

• primary tumour at lymph node - low stage, good prognosis
• secondary tumour, metastasised from elsewhere - high stage, poor prognosis -> quickly look for primary tumour to treat!